1. The Internal Filter provides effective filtration and increases the oxygen level to ensure a clean tank environment. It features fine cleaning effect, quietness and easy maintenance. Fit for shrimp, fry and various ornamental fish like betta, discus, guppy, and goldfish. 2. Provides both mechanical and biological filtration for your tank. The air infusion chamber produces numerous minute bubbles which promotes gas exchange process and increases dissolved oxygen level in water. Good to use in both fresh and saltwater tanks. 3. Easy to set up - Just connect the unit with an air pump thru an airline. It provides both aeration and filtration for your tank.